rs779805 Von Hippel-Lindau Gene Polymorphism Induced/Related Polycythemia Entity, Clinical Features, Cancer Association, and Familiar Characteristics.

Increased red blood cell count may result from primary erythrocytosis (polycythemia vera), but it is often due to secondary causes with increased erythropoietin levels. Secondary erythrocytosis may also be congenital due to different gene mutations of hemoglobin, hemoglobin stabilization proteins, EPO receptors, or oxygen sensing pathways. Von Hippel- Lindau gene mutation causes altered tissue oxygen sensation in VHL disease, usually with normal hemoglobin. Germline VHL mutations associate with classical VHL disease and represent genetic susceptibility for pheochromocytoma. VHL polymorphisms are mostly considered an innocent phenomenon. Still, some data indicate that these polymorphisms are not always harmless and can occur with prostate, renal, and colon cancer or even with isolated erythrocytosis. Seventy-eight patients referred to our department with elevated hemoglobin were screened for VHL mutations. There were no classical somatic VHL mutations. However, we found heterozygous (GA) or homozygous (AA) rs779805 VHL c.-195G>A polymorphism accompanied by erythrocytosis. These patients are Jak-2 negative, with normal or elevated EPO levels, sometimes with family accumulations and often phlebotomy needs, and in some cases with malignancies in the family. No other cause of erythrocytosis was found. We use phlebotomy regularly, and for those with cardiovascular risk factors, we recommend aspirin.

A novel flow cytometric method for enhancing acute promyelocytic leukemia screening by multidimensional dot-plots.

Acute promyelocytic leukemia (APL) is generally characterized by t(15;17)(q24;q21). In some cases, the classic translocation cannot be identified by conventional methods, since the PML-RARA fusion protein results from complex, variant, or cryptic translocation. The diagnostic algorithm of APL starts with screening methods, such as flow cytometry (FC), followed by fluorescence in situ hybridization or polymerase chain reaction to confirm the diagnosis. Our aim was to develop a novel protocol for analyzing APL samples based on multidimensional dot-plots that can provide comprehensive information about several markers at the same time. The protocol included four optimized multidimensional dot-plots, which were tested by retrospective reanalysis of FC results in APL (n = 8) and non-APL (n = 12) acute myeloid leukemia (AML) cases. After predicting the potential position of hypergranular- and microgranular-type aberrant promyelocytes, the percentages of blast populations were examined within the gates in all AML cases. The percentage of blasts in each predefined gate was well above the cut-off value (95%) in APL cases in all tubes. In non-APL AML cases, the percentage of blasts in the same gates never reached the cut-off value in all investigated tubes, and even when it did in a single tube, the pattern was markedly different from that observed in APL cases. In conclusion, multidimensional dot-plots can be used for screening APL even in cryptic APL cases, although reproducibility across several laboratories would require standardization of antibodies and fluorochromes. This easy-to-use and quick method can support the diagnosis of APL and the prompt initiation of the appropriate treatment.

Dasatinib inhibits coated-platelet generation in patients with chronic myeloid leukemia.

Since the introduction of tyrosine kinase inhibitors, the overall survival of patients with chronic myeloid leukemia has markedly improved. However long term use of these drugs results in various adverse events. Treatment with second generation dasatinib is often complicated by hemorrhagic events. Previous lumi-aggregometry studies have shown impaired platelet function in patients on dasatinib therapy. Dual agonist activated platelets (coated-platelets) are also sensitive indicators of platelet function. We hypothesized that dual activation with convulxin and thrombin of platelets in a flow cytometric assay could be a more sensitive method for detecting platelet dysfunction as compared to single agonist studies used in lumi-aggregometer. Platelets of healthy volunteers incubated with dasatinib as well as platelets from patients on dasatinib therapy were investigated. Low therapeutic plasma level dasatinib concentrations at which a considerable reduction in coated-platelet generation was observed in vitro, did not cause detectable change in platelet aggregation response. Coated-platelet assay and lumi-aggregometry were also investigated at 0, 1 and 4 hours after drug administration in dasatinib treated CML patients. Significant decrease was observed at 1 hour in maximal aggregation by collagen. Although the aggregation curves became normalized by 4 hours, coated-platelet generation was still inhibited in dasatinib treated patients. Nilotinib, another second generation tyrosine kinase inhibitor, had no effect on aggregation and on coated-platelet formation neither in vitro nor in ex vivo samples. At therapeutic plasma levels coated-platelet assay is more sensitive than lumi-aggregometry studies for the demonstration of the inhibitory effect of dasatinib on platelet function.

[Drug treatment of acute myelogenous leukaemia. Current options and future perspectives]. / Az akut myeloid leukaemia gyógyszeres kezelése. Jelenlegi lehetoségek, jövobeli kilátások.

Acute myelogenous leukemia is a heterogeneous disease. Recent molecular mutational analysis techniques have shed more light on different, genetically well characterised types of the disease. Treatment approach is uniform except for acute promyelocytic leukemia. Application of the "3 + 7" induction treatment has been the gold standard in the past 40 years. While the dose of cytarabine has not been changed, escalating daunorubicine dose in younger (<60 years) patients with good performance status to 90 mg/m(2) had a positive impact on overall survival. High dose chemotherapy is tolerated poorly in patients older than 60 years of age and, as treatment is not curative in the elderly, improvement of overall survival and quality of life remains the main goal of management in these patients. Low intensity treatment is beneficial and can provide additional advantage over supportive care. Innovative and targeted therapy approaches might give promise to better management of patients with acute myelogenous leukemia.

[Treatment of acute myeloid leukemia -- a single center experience (2007-2013)]. / Heveny myeloid leukaemiás betegeink kezelésével szerzett tapasztalataink (2007-2013).

INTRODUCTION: Mortality of acute myeloid leukemia is still 60-70% in young (<60 years) adults and 90% in elderly (≥60 years) patients. AIM: The aim of the authors was to analyse the outcome of treatment in their patients with acute myeloid leukemia. METHOD: From 2007 to 2013, 173 patients with acute myeloid leukemia were treated. Patients were classified according to the European LeukemiaNet prognostic guideline. Association between mortality and the type of acute myeloid leukemia (secondary or primary), dose of daunoblastin at induction of treatment, and the rate of minimal residual disease were investigated. RESULTS: The 5-year survival probability was 25% in young adults and 2% in the elderly. The survival was significantly influenced by these prognostic factors. The 5-year survival rate was 50% in the young, favorable prognostic group. The 90 mg/m2 daunoblastin dose was found to be beneficial. Addition of bortezomib to the standard induction protocol had an additional beneficial effect. CONCLUSIONS: The speed and depth of the response to induction therapy, and the initial white blood cell count had an apparent effect on survival.

Comparison of coated-platelet levels in patients with essential thrombocythemia with and without hydroxyurea treatment.

Essential thrombocythemia (ET) is an acquired myeloproliferative disorder with sustained increase of platelet count. This disease may be associated with thrombotic or bleeding complications due to the altered number and function of platelets. Coated-platelets produced by a simultaneous activation of collagen and thrombin represent a subpopulation of activated platelets with high prothombinase activity and the retention of several α-granule-derived coagulation factors on their surface. There is a growing body of evidence for a relationship between variable levels of coated-platelets and different hemostatic alterations. However, no data are available on coated-platelet formation in the pathogenesis of ET in the presence or absence of treatment. The levels of coated-platelets in 43 ET patients (15 non-treated and 28 hydroxyurea-treated) without known thrombotic or hemorrhagic complications were analyzed using flow cytometry. These results were compared with data of 31 healthy individuals. In addition, platelet function was analyzed with PFA-100 analysis, and P-selectin (CD62) positivity was also measured by flow cytometry. Increased P-selectin expression was detected with prolonged PFA-100 closure times in the ET group; however, significantly lower levels of coated-platelets were found in non-treated ET patients compared to controls (23.1 ± 8.8% vs. 37.6 ± 12.7%, p = 0.0008). This tendency was more evident in patients with JAK2-V617F mutation. Patients on hydroxyurea treatment had elevated coated-platelet levels (34.1 ± 12.3%) close to the normal value. In conclusion, lower than normal levels of coated-platelets were generated in ET, which were significantly (p = 0.0008) increased by hydroxyurea treatment. We suppose that abnormal coated-platelet level may also contribute to platelet dysfunction in ET.

[Current treatment of acute myeloid leukaemia in adults]. / A felnottkori heveny myeloid leukaemia korszeru kezelése.

Recent cytogenetical findings and novel molecular biology results of acute myeloid leukaemia have shed new lights of our understanding in the diagnosis and treatment of the disease. Acute myeloid leukaemia is not only represented by the wide variety of morphological and immunophenotypic diversity but also demonstrates cytogenetical and molecular biological heterogeneity of its own. It has an unfavorable prognosis, especially in the elderly. Overall survival of younger patients (<50-60 years) has increased in the past years due to high dose chemotherapy (daunorubicine, cytarabine). But in case of unfavorable prognostic factors (not only cytogenetical but also molecular biological characters of the disease), allogeneic stem cell transplantation is needed for successful overall outcome. Better understanding the biology of acute myeloid leukaemia could establish novel targeted therapies and help us eventually to cure the disease.

[Practical considerations and questions in the treatment of chronic lymphocytic leukemia]. / Gyakorlati szempontok és kérdések a krónikus lymphoid leukaemia kezelésében.

Understanding the pathogenesis and refine the treatment of chronic lymphocytic leukemia have been tremendously improved in the past decade. Treatment outcome and estimated prognosis have become more accurate due to the advanced molecular biological techniques and the classical prognostic markers. Incorporation of fludarabine and rituximab into the standard protocols fundamentally improved treatment outcome in chronic lymphocytic leukemia. Chemoimmunotherapy has improved not only the remission rates but had a significant impact on overall survival, as well. Eliminating residual leukemia and achieving complete hematological remissions at such high rates establish potential background for cure. Still, a great deal of dispute has been emerged regarding everyday clinical practice. Authors present their institutional experiences and review the literature.

Tetraspanin CD9 is required for microparticle release from coated-platelets.

CD9, a member of the tetraspanin superfamily, is the third most abundant protein on the platelet surface, but its function remains unknown. In this report, we demonstrate that CD9 is required for the release of microparticles from coated-platelets. Coated-platelets are formed as a result of dual agonist activation with collagen and thrombin, and each coated-platelet releases 15-25 microparticles averaging 0.4 microm in diameter. We report here that four separate monoclonal antibodies against CD9 inhibited microparticle release from coated-platelets by 72-102% with an IC(50) of approximately 500 ng/mL for ALB6 and SN4. In addition, the anti-alpha(IIb)beta(3) monoclonal antibody AP2 also inhibited microparticle release although additional anti-alpha(IIb)beta(3) monoclonals did not. These data support participation of the tetraspanin CD9, together with the integrin alpha(IIb)beta(3), in the membrane vesiculation process associated with platelet microparticle release.

[One hundred fifty autologous peripheral haemopoietic stem cell transplantations and their lessons]. / Százötven autológ perifériás haemopoeticus ôssejt transzplantáció és tanulságai.

UNLABELLED: Five years ago (in September, 2003), the activity of the 5th Haemopoietic Stem Cell Transplantation Centre of Hungary has begun. This centre has been registered as No 648. by the European Group for Blood and Marrow Transplantation-Centres. AIMS: To supply the needs of stem cell transplantation regions in north-east Hungary and to develop an active co-operation with the Hungarian and international centres. METHODS: Transplantations were made according to international criteria. RESULTS: 150 autologous stem cell transplantations has been performed so far, including 74 patients with myeloma multiplex, 43 patients with non-Hodgkin lymphoma, 27 patients with Hodgkin's disease, 4 patients with autoimmune disease, and one patient with leiomyosarcoma. The survival rates were similar to the previous Hungarian and international data. The centre played a role in other activities using stem cell therapy at the University of Debrecen (dendritic cell vaccine program, stem cell therapy in myocardial infarction, stem cell therapy in peripheral arterial- and autoimmune diseases). This centre performed the largest quantity of the conditioning protocol Zevalin, Bischloronitrosourea, Etoposide, cytosine-Arabinoside, Melphalan in non-Hodgkin lymphoma in Hungary; ten patients were treated with this protocol.

[Transformation of chronic lymphocytic leukemia to myelodysplastic syndrome: case presentation and review of the literature]. / Krónikus lymphoid leukaemia transzformációja myelodysplasticus szindrómába: betegismertetés és az irodalom áttekintése.

Chronic lymphocytic leukaemia (CLL) may transform to either malignant lymphoid disorder or increase the occurrence of solid neoplasms. However myeloid malignancies seldom develop. We report a case of a patient who has remained untreated for CLL and developed myelodysplastic syndrome (refracter anemia with ringed sideroblasts) six years after the diagnosis of CLL. Development of myelodysplastic syndrome resulted in concurrent attenuation of CLL. Discussion of the pathogenesis of myeloid disorders occurring with CLL and review of the literature are also presented.

Role of mitochondrial permeability transition pore in coated-platelet formation.

OBJECTIVE: Coated-platelets are a subset of cells observed during costimulation of platelets with collagen and thrombin. Important characteristics of coated-platelets include retention of multiple alpha-granule proteins and expression of phosphatidylserine on the cell surface. The mitochondrial permeability transition pore (MPTP) is a key step in apoptosis and is suggested to be involved in some forms of platelet activation. The objective of this study was to examine the role of MPTP in the synthesis of coated-platelets. METHODS AND RESULTS: Flow cytometric analysis of coated-platelet production was used to examine the impact of pharmacological effectors of MPTP formation. Cyclosporin A, coenzyme Q, and bongkrekic acid all inhibit MPTP formation as well as production of coated-platelets. Phenylarsine oxide and diamide, both potentiators of MPTP formation, stimulate coated-platelet synthesis. Atractyloside, another inducer of MPTP formation, does not affect the percentage of coated-platelets synthesized; however, it does increase the level of phosphatidylserine exposed on the surface of coated-platelets. CONCLUSIONS: These findings indicate that MPTP formation is an integral event in the synthesis of coated-platelets. Although the exact function of the MPTP remains to be determined, these data support a growing body of evidence that apoptosis-associated events are vital components of the platelet activation process. Formation of coated-platelets involves a complex set of activation events initiated by dual agonist activation. The mitochondrial permeability transition pore (MPTP) is a key intermediate in apoptosis and has been suggested to impact platelet activation. This report demonstrates that MPTP formation is essential to production of coated-platelets.

[Prognositc value of CD38 cell surface marker in chronic lymphocytic leukemia]. / CD38 sejtfelszíni marker prognosztikai jelentósége krónikus lymphoid leukaemiában.

CD38 is expressed on the surface of leukemic cells in a significant percentage of patients with B-cell chronic lymphocytic leukaemia (CLL). From the literature it is known that CD38 expression has prognostic value in CLL, suggesting an association between CD38 expression and the mutational status of IgV genes. Peripheral blood samples from 82 patients with CLL were analyzed by flow cytometry for CD38 expression on CD19+ leukemic cells. CD38 was expressed in 30% or more of leukemic cells in 26 patients (patients with 30% or more B cells coexpressing CD19/CD38 were considered positive). Seven of the 26 patients with high CD38 expression and eight of the 56 patients with low CD38 expression had advanced-stage disease (RAI III-IV). Higher than 4 mg/l levels of beta 2-microglobulin was measured in the serum of nine of 26 CD38+ and seven of 56 CD38- patients. Our analyses showed that the high CD38 expression is associated with other risk factors, identifying an aggressive disease, which require treatment. It will be important to conduct further studies to establish the prognostic value of the high CD38 expression in early-stage disease.

[Experience with fludarabine treatment and review of the literature]. / Fludarabinkezeléssel szerzett tapasztalataink és az irodalom áttekintése.

INTRODUCTION: Fludarabine is the most commonly used purine analog, its mechanism of action is complex. Fludarabine inhibits DNA synthesis, acts on non-dividing (G0 phase) cells influencing apoptosis. PATIENTS, RESULTS, CONCLUSIONS: In our institute 47 patients were treated with fludarabine or fludarabine based combination chemotherapy. Fludarabine was given in 19 patients with chronic lymphocytic leukaemia (CLL), complete remission (CR) was achieved in one case, partial remission (PR) was obtained in 10 patients. Fludarabine was more effective in patients who received less intensive chemotherapy prior to fludarabine therapy and in those patients who had less advanced diseases. Elderly patients (over sixty years of age) also responded to fludarabine therapy. Fludarabine and cyclophosphamide combination (FCy) were used in three lymphocytic lymphoma patients, two of them obtained PR, in the third case the disease progressed. Fludarabine + mitoxantrone (Novantrone) + dexamethasone (FND) regimen was administered in nine patients who were previously heavily treated (one patient with B-CLL, one with T-CLL, one with peripheral T-cell lymphoma and six with indolent B-cell lymphoma). More patients and longer follow up is needed to determine the efficacy of FCy and FND protocol. FLAG-IDA (fludarabine, high dose Ara-C, granulocyte colony-stimulating factor, idarubicin) was applied in 16 acute leukaemia patients with poor prognosis including therapy refractory and relapsing cases. Three CR and two PR, one CR and three PR was achieved in nine patients with acute myeloid leukaemia and in seven patients with acute lymphoid leukaemia, respectively. For this reason, despite the short period of remission, this regimen can be recommended to patients who are candidate for stem cell transplantation.

[Paroxysmal nocturnal hemoglobinuria]. / Paroxysmalis nocturnalis haemoglobinuria.

The current knowledge of the history, clinical course, diagnosis and treatment of Paroxysmal Nocturnal Hemoglobinuria (PNH) are summarized in this article.